Tube rack



FIG. 1 is a top perspective view of a tube rack;

FIG. 2 is a bottom perspective view of the tube rack;

FIG. 3 is a top view of the tube rack;

FIG. 4 is a bottom view of the tube rack;

FIG. 5 is a front view of the tube rack;

FIG. 6 is a back view of the tube rack;

FIG. 7 is a first side view of the tube rack; and,

FIG. 8 is a second side view of the tube rack.

CLAIM The ornamental design for tube rack, as shown and described.